I do think DJ Moore is a good fit for Fields. Good route runner - creates seperation. If Mooney is back to healthy with Claypool and Kmet that is a way better receiving corps. Good speed, plus some size. Velus as a gadget guy and ESB as a depth piece.
Seperately - get an explosive running back, upgrade line, and this offense is much better on paper than where they started last year. And if Fields doesn’t work - you have 2 frp next year to turn into your next qb.